Rim-gripping cartridge belt link



United States Patent RlM-GRIPPING CARTRIDGE BELT LINK Harlan C. Clark, Oxford, and Roy S. Sanford, Woodbury, Conn., assignors to the United States of America as represented by the Secretary of the Army Application August 28, 1957, Serial No. 680,900

1 Claim. (Cl. 8935) This invention relates to ammunition links for highspeed automatic guns and is more particularly directed to the retention of cartridges in a link of the open type from which the cartridge is stripped substantially at right angles to the longitudinal axis thereof.

One of the many problems encountered in feeding relatively long belts of ammunition into high-speed automatic guns is the tendency for the cartridge to become tilted in the link as a result of the inertia forces imparted to the belt by the intermittent feeding movements thereof during burst firing of the gun. These inertia forces cause the ammunition belt to surge and form a series of progressive waves which in turn impart a vertical whipping movement to whatever portion of the belt may be freely suspended between the gun and the source of ammunition. In the case of links which are of open construction throughout the entire length thereof, such whipping movement pivots the cartridge about the point at which the link is in resilient engagement therewith.

It has been found that the tilting movement thus imparted to the cartridge is often of sufficient severity to cause the forward end thereof to protrude beyond the envelope formed by the link. Such condition could very likely cause a feeding jam as the protruding end of the cartridge is drawn into the opening in the feed unit of the gun. Even if the interference between the cartridge and the feed entrance should not be enough to effect a stoppage of gun operation, the impact on the protruding portion of the cartridge is usually of sufiicient severity to effect a substantial degree of deformation therein. Obviously, this cannot be tolerated in those instances where the cartridges are of large enough caliber to include a detonation fuze therein.

While the aforesaid undesirable displacement of the cartridge in the link may be prevented by decreasing the resiliency of the clamping engagement of the link, it is apparent that this approach will interfere with the ease with which the cartridge may be stripped therefrom prior to being chambered in the barrel of the gun. Any increase in the force required to strip the cartridge from the link will obviously tend to reduce the maximum rate of fire which can be attained by the gun.

Accordingly, it is an object of this invention to provide a cartridge belt link of the open type having improved means for releasably retaining the cartridge therein.

It is a further object of the present invention to provide a cartridge belt link of the type from which the cartridge is stripped substantially at right angles to the longitudinal axis thereof wherein the means for restraining the cartridge against forward or angular displacement therein does not increase the degree of force required to strip such cartridge from the link.

A more specific object of this invention lies in the provision of a sturdy, unitary, open-sided link having means engageable with the extractor groove of the cartridge for effecting positive restraint against any tilting move- ICC ment thereof out of parallelism with the longitudinal axis of the link.

In carrying out the invention in one form, a unitary cartridge belt link of the open type is provided with a longitudinal body portion terminating at the rear end in a cartridge holding portion having a depending tab on either side thereof for resiliently gripping the body of the cartridge. The upper section of the cartridge holding portion is cut away to leave a transverse arcuate band having a centrally-disposed rectangular segment projecting rearwardly and downwardly into the annular extractor groove of the cartridge case so as to lie immediately in front of the rim portion thereof. The cartridge holding portion is also provided with a strap portion extending transversely across the rear end thereof to prevent rearward displacement of the cartridge. In addition, the strap portion cooperates with the rearwardly extending rectangular segment in the top. of the link to positively restrain the cartridge from tilting forwardly and downwardly about the cartridge gripping tabs.

The specific nature of the invention as well as other Fig. 5 is an elevational view of the rear end of a link having an alternate cartridge-gripping construction; and Fig. 6 is a cross-sectional view taken along line 6'--6 in Fig. 2.

Referring more particularly to the drawing, theinvention is embodied in a unitary cartridge belt link having a longitudinal body portion 12 which includes a transverse C-shaped loop 13 of channeled cross-section arranged to cooperate with a suitable independent connector (not shown) for providing the releasable connection through which the individual links are joined to form a continuous articulated belt. The forward end a of body portion 12 terminates in a pair of oppositelydisposed legs 14 which complete the link envelope andensure substantially uniform stacking when the belt is arranged in a series of superimposed layers in a conventional ammunition box.

A pair of spaced-apart rectangular arms 15 project from either side of the rear end of bodyvportion 12and extend downwardly and rearwardly therefrom to wterminate in an inwardly bent tab 16 depending below the centerline of a cartridge 17 to be retained in the link. Tabs 16 may be of any shape as long as they are provided with inwardly-directed detents 18 disposed in resilient engagement with the exterior periphery of cartritliige 17 for releasably retaining such cartridge in the Each arm 15 is longitudinally continued beyond tab 16 to form a substantially rectangular extension 19 terminating in an inwardly turned strap portion 20 extending substantially at right angles to the longitudinal axis of body portion 12. An arcuate band 21 extends transversely between extensions 19 and is centrally provided with a forwardly-directed rectangular stripping lug 22 disposed in axial alignment with a similar but rearwardly directed lug 23 at the forward end of body portion 12.

Pat e 6. 9,

emanate rectangular projection 24 having a beveled terminal edge 25.

In order to assemble cartridge 17 into a link, the case portion thereof is placed against tabs 16 with the annular rim 26 in vertical alignment with the space left between strap portions 20 and rectangular projection 24. Thus, when cartridge 17 is forced past resilient tabs 16, the beveled edge 25 of rectangular projection 24 will enter into the extractor groove 27 formed around the rear end of the case portion. It is, therefore, readily apparent that straps 20 effectively prevent any rearward displacement of cartridge 17 in the link. At the same time, any tendency of cartridge 17 to tilt about the point of contact thereof with detents 18 in tabs 16 is positively restrained by the resulting engagement of rectangular projection 24 with the front face of annular cartridge case rim 26. Since the area of engagement between the beveled edge 25 of projection 24 and rim 26 on cartridge 17 is relatively large, the possibility of any shearing through rim 26 is fairly remote. 7

As has been previously mentioned, the slack portion of the ammunition belt between the storage area and the gun itself undergoes considerable whipping or snapping movements during the accelerations imparted thereto by intermittent firing. It has been found that the inertia forces produced by the resulting wavelike movements of the ammunition belt are concentrated at the center of gravity of each cartridge. Inasmuch as the center of gravity is located nearer the base of the cartridge than the bullet end thereof, the resultant of these inertia forces tends to tilt such cartridge out of engagement with tabs 16 of the retaining link. Such tilting of the cartridge is, however, effectively blocked by straps 20 and projection 24 in the manner explained above.

Moreover, inasmuch as cartridge 17 is arranged to be laterally stripped from the link, i.e., in a direction substantially at right angles to the longitudinal axis thereof, the only force to be overcome is that provided by the resilient gripping engagement of tabs 16. Even if cartridge 17 should contact either projection 24 or strap portions Zilduring the stripping from the link, the resulting frictional resistance therebetween would not increase the required stripping force to any appreciable degree. However, cartridge 17 is ordinarily seated in the link with a small clearance in relation to both projection 24 and strap portions 20 and, therefore, will not come into contact therewith so as to increase the degree of force required to move the case portion out from between resilient tabs 16.

As shown in Fig. 4, the means for preventing rearward displacement of cartridge 17 may consist of a pair of inwardly-turned strap portions 28 each having a depending arcuate section 29 which mates to form a semicircular end member substantially concentric with the base of cartridge 17. Such mating engagement may be provided by uniting sections 29 into a dovetail connection 30 and welding or brazing the joint thus formed as best shown at 31. Although considerably more diffi- .wltt t qrmt the tear. s tl. .t112. 1 i 1 .s. also a one-piece member integral with extensions 19.

The cartridge gripping function of the link may be enhanced by changing the configuration of arms 15 to that shown at 32 in Fig. 5 and providing an elongated rectangular slot 33 adjacent the lower edge of each arm 32 and parallel thereto. In addition, tabs 16 may be replacedby outwardlyppening Y;shaped ears.34. 1 Such construction increasesthe resiliency with which the link grips cartridge 17 inasmuch as any tendency of ears 34 to spread apartis additionally resisted, by the torsional effect of the relatively narrow portion from which such ears depend. p 4

Accordingly, there is here provided a superior cartridge retaining structure for a link Whose efiiciency remains unaffected by the relatively large tensile forces imparted to the remaining portion of the link during the high-speed feeding of ammunition belts of considerable length. Moreover, the cartridge ispositively restrained against movement in the link in every direction except at rightangles to the longitudinal axis thereof. In addition, unlike prior art links, the improved means of the present invention for preventing tilting of the cartridge in the link is entirely independent of the forces involved in the lateral stripping of the cartridge therefrom prior to being chambered in the barrel of the gun.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claim is intended to include such variations.

l aimz V M In a cartridge belt link, a longitudinal open body pot-,- tion, a pair of inclined arms extending downwardly and rearwardly from opposite sidesof said body portion, each of said arms terminating in an inwardly bent depending tab for resiliently gripping the side of the cartridge below the central longitudinal axis thereof, said arms having rearwardly projectingextensionsterminating in opposed inwardly-turned strap portions extending transversely across the rear end of the link, an arcuate band extending upwardly between said extensions in coaxial alignment with said body portion; and an inclined rectangular section extending downwardly and rearwardly from said band to project into the annular extractor groove in the cartridge forwardly of the rim portion thereof to positively restrain the cartridge against tilting about the point of contact with said tabs.

References Cited in the file of this patent UNITED STATES PATENTS 1,328,356 Ballard Jan. 20, 1920 2,222,812 Faulkner et al. Nov. 26, 1940 2,780,963 Dixon Feb. 12, 1957 2,804,807 Dixon Sept. 3, 1957 v FOREIGN PATENTS 507,739 Great Britain June 20, 1939 

